Aerosound RC SOUND System Review

If you want an authentic scale model, don't overlook the sound of your plane in operation! Mike Heer updates his Great Planes Fokker Dr-1 60 to give it the sound of a real plane with Aerosound's RC sound system.

Introduction

While I love flying electric planes, there are times when I miss aspects of glow powered planes. Building glow planes involves two of my senses not much engaged by electrics: smell and hearing. I love the slight whiff of burning glow fuel and the roar of the engine on takeoff and during fly bys. One of my favorite amateur video clips involves flybys by a full scale Mustang powered by a Merlin engine. I listen to that video clip more than I watch it.

Now, thanks to Aerosound RC, I have added sound to one of my largest powered electrics and the change is AMAZING! My converted electric Great Planes Fokker Dr-1 60 (not currently available) is very quiet, and I could clearly hear the sound of the rotary motor playing on my Aerosound RC sound system synchronized to the actual running speed of the Fokker's Kontronic brushless motor. While this sound system isn't for little park flyers, it adds tremendous realism via authentic sound to larger planes. My Dr-1 has always been well received at the flying field, but with the addition of sound... WOW!

Note: The amplifier does get warm during use. Position it safely in the fuselage where there will be air flow to cool it and keep it away from any flammables. I strongly recommend using the optional heat sinks that they sell to help keep the amplifier cool. Don't touch the metal bar on the amplifier while it is in operation or immediately after running the unit.

Other Items Needed:

Soldering Iron

Solder

Flux

3 or 4 cell LiPoly battery pack to power the amplifier*

Connectors for amplifier and battery pack

Mounting Hardware

Materials to make "sound box" for speakers

Optional Heat Sink is highly recommended

The amplifier can be powered by the motor batteries but I chose not to do that.

Product History

This sound unit was designed by Benedini RC-Electronics in Europe and is imported to the US exclusively by Aerosound RC. Benedini makes a number of different sound units for model tanks and surface units as well as a smoke generator and this sound unit for airplanes - all quality hobby grade products. This unit is lightweight and has two amplifier and speaker optoins. I have the smaller of the two amplifiers and only used a 3-cell LiPoly to power my ampilifier, so much more sound is available if needed. The sound unit plugs into the amplifier, but the amplifier requires some soldering to connect to the speakers and power supply.

Assembly

The first step was simply plugging it into the amplifier and the receiver and adding the ESC via the attached Y-connector. The micro sound unit came assembled and programmed. I had to plug one servo type connector, he other side had a Y-connector. The ESC was plugged into a female socket on the Y-connector and the male connector plugged into the receiver in the throttle port (the receiver's power CANNOT exceed 5 volts). Since I use a separate four cell 4.8 volt battery pack to power the receiver and servos in the plane, that was not a problem. The motor/throttle and ESC Y-connection synchronizes the motor sounds to the speed of the motor. Machine gun and cannon sounds can also be remotely activated with some of the motor sound units requiring a second connector cable (not supplied) to plug into an unused channel on the receiver.

The amplifier needed several items soldered onto its multiple wires. The amplifier required a separate and larger power source then the sound card. While it could be powered by the main motor battery I chose to power it separately. Accordingly, I started by soldering a Deans Mini connector to its power wires so it could be powered by a 3 or 4 cell LiPoly battery (the low voltage unit runs off of 11-18 volts). I decided to use a 3 cell LiPoly because I had several on hand, and they were equipped with a Deans mini connector. These battery packs will easily handle several full flights.

Next I had to decide where the speakers were going to be located within the fuselage and if the 9 inches of wire per speaker was enough or if I needed to add wire. I determined the location and that no additional wire was necessary, but I decided to make the system so that it could be plugged together or unplugged as needed, recommended in the instructions as speakers might be damaged in operation. While a variety of connectors could be used, I soldered an old style Airtronics female aileron extension wire plug to each of the two speakers using the black and red wires only. I soldered two matching male plugs to the amplifier using just the black and red wires. The speakers can now be plugged in, and more importantly, the speakers can be unplugged and left in the plane if I want to use the amplifier in a different plane, or I can more easily replace a speaker in the future as needed.

At this point I had the unit wired, but not installed, so I decided to connect it and test it out. I used a receiver and receiver battery awaiting installation into another project just to test out the system per the photos below. I turned on my transmitter and set the throttle at low and plugged the battery into the receiver and the Lipoly into the amplifier. The sound of an engine came on LOUD and strong but the throttle was in the Off setting. DOH! I had to program it for this setup.

Soldering

I once was horrible at soldering. Since good soldering is important to this sound system, I thought I would cover Flux, the material that turned me into a person skilled at soldering.

When soldering two wires together, I stripped the ends of the wire. I placed a piece of heat shrink tubing onto one side of the wire and then twisted the wires together. I used a toothpick and spread some Flux over the wires on all sides. When my soldering iron was nice and hot, I touched it to some solder over and onto the twisted wire connection. The solder almost spread itself smoothly over the wire. One quick pass with the iron on both sides, and I had a perfect connection. I covered the wire with the shrink tubing and shrink the tubing with my Monocoat heat gun. The flux helps the soldering to cover smoothly and evenly, making for a better connection with less solder.

For soldering a wire to a Deans connector, first I put some Flux on the side of the Deans connector I wanted the wire soldered onto, and dipped the wire's end into the Flux. With the iron hot, I got a little solder onto the tip of the iron and spread that solder onto the end of the wire and got a fresh drop of solder onto the Dean's connector where I wanted the wire, a process called “tinning” the surfaces. I held my Deans connector in place using a locking vice grip as shown below. With one hand holding the wire in place on the solder on the Dean's connector, with the other hand I placed the hot iron to the back side of the connector. I quickly saw the solder liquefy. I held the wire firmly in place and removed the soldering iron. In two second the solder connection was done. When it had cooled I pulled the heat shrink tubing over the now soldered wire connection. Using my heat gun I shrank the heat tubing in place. Flux makes for a much better connection and an easier soldering process. Flux and heat shrink tubing can be purchased at most Radio Shacks and other electrical stores.

The System's Power

The micro sound circuit that plugs into the receiver is powered by the same battery pack that powered my receiver. It draws its power from the receiver just like a servo. They reported that it draws less juice than a small servo to operate. I went with a separate small 1100 mAh 3-cell LiPoly pack to power the amplifier. For louder sound, a 4-cell LiPo can be used. Thus the addition of sound had no effect on my flight times other than for the extra ounces the plane was now hauling as a result of adding the sound unit, speakers and LiPo battery pack.

the Auto Start mode

I disconnected the amplifier from the TBS Micro sound card and opened the instruction manual to this: "Teaching the Auto Start mode: 1) Power on transmitter and receiver. LED (on sound card) blinks fast ->normal mode. Bring throttle stick to idle. Motor must not move. 2)Bridge LRN (see picture below) contact for about .5 seconds until beep->LED continues on. At this moment the idle position of the throttle stick is stored. 3) Move throttle stick to your desired acceleration point (Throttle stick position where idle dead band stops and engine running sound starts.) and wait for a beep. Now the dead (neutral) band of the speed channel is defined. 4) Move the throttle stick to full speed position and wait for three beeps. After this the sound unit is back in the normal operation mode.”

To hear the beeps, the amplifier had to be connected to the sound card and the speakers and powered by its battery as well. It took me only ten minutes to program the sound to work with my transmitter's throttle, and most of that time was reading the instructions.

Downloads

The Machine Gun Connection

My sound card had the sound of a Spandau machine gun programmed in the second position on the sound card. Unfortunately, no connecting wire was supplied to connect position 2 and link it with my receiver. Furthermore, both the receiver and the sound card needed male connectors. I took two servo extension wires and cut them in half and soldered the two male ends together to connect the machine gun sound port to the receiver. I plugged the connection wire into the landing gear channel on my receiver. I planned to activate and stop my machine guns by toggling that switch. I connected the sound cart port 2 to the receiver port five and turned on the battery and immediately the machine guns started blasting. I toggled the landing gear switch to the other position to turn off the machine guns, and they just kept blasting. I shut it down and tried reversing the switch in my transmitter, but the second try was the same as the first. I tried disconnecting the positive wire in the plug to see if that made a difference, but it didn't. I tried a number of different things but I won't bore you with any more of my failures.

I sent an e-mail about my problem to AeroSound RC, and they sent a short response which, among other things, suggested that I adjust the movement distance programmed in the transmitter and controlled by the switch. When I did that for channel five on my computerized transmitter, I suddenly gained control of my machine gun sound. By expanding the range of movement for the switch in my computer’s software, I had control using the three wire connector. Toggle on, and the machine guns fired. Toggle off, and they stopped. This was great! I hadn't been using the fifth channel on my receiver for this plane prior to this. Flush with my success, I was, to quote Dickens: "As giddy as a school boy!"

Downloads

Aerosound, we Have a Problem

I was feeling proud of solving the machine gun issue, and I connected everything together for a final test. I turned on the receiver, and three seconds later the motor sound turned on without my touching the throttle. It ran momentarily, and then shut down. I tested the machine guns and they worked as they should. With the machine guns connected but not being "fired," the engine sound kept cycling on and off and didn't respond properly to my throttle commands. After a cycle it would be off three seconds and then back on through another cycle. This was interrupted only briefly when I fired the machine guns. The gun sound was working perfectly. AAUUUGGGH!

The Solution

I decided to program the Autostart anew, with everything connected (the machine gun was not connected when I did the programming the first time). That did the trick! Problem solved by programming the Auto Start with the machine gun connected to the sound system. As with many things in life, the solution was very easy... once I knew what to do.

Installing the System into the Fokker Dr-1

Having confirmed that the system was working properly, the next step was installing the speakers into the plane. I am a lazy dog at times and looked for the simplest way of doing it. Having the plug in connector for the speakers made the mounting process easier, still they needed to be installed so they could be removed if they fail and where the air pushed into the fuselage won't prevent the speakers from moving properly. Finally, I knew they might need a sound box or boxes to perform their best (sound boxes are like speaker boxes, controlling the movement of air and amplifying the sound). I initially chose to mount one speaker facing forward inside the fuselage near the front of the middle wing and the second speaker facing down in the fuselage behind the wing. The problem was that the speaker behind the wing threw off the CG. I decided to try it with just the one speaker (the instruction manual said there wasn't much difference between using one and two speakers) in the fuselage facing forward. If that didn't provide enough sound, I could try a different mounting location in the future.

What I probably should have done was make a wooden speaker/motor mounting box for the front of the plane under the cowl. There was enough room to do it, and it probably would have allowed me to remove some of the lead I used to obtain the proper CG balance in the first place.

The Common Sense 75 Opto ESC

For this review I upgraded the plane’s ESC to a larger ESC since my original 40 Amp ESC was struggling with the size of props that best pulled the plane. The new ESC is the Common Sense 75 Amp Opto ESC. With this upgrade I have been able to increase the prop size by an inch, and I can run at full throttle even on hot days without stressing the ESC's capacity. There is no BEC, so my receiver, servos and now the sound micro control unit are powered off of a separate 4-cell battery pack. This battery pack has 4.8 volts and that is important since the voltage must be kept below 5 volts for the micro control unit.

The Common Sense ESC worked perfectly in my Fokker! No accidental cut-offs from my voltage draw for the motor as I was well within the ESC's capacity with lots of amp draw to spare. The ESC also worked well with the sound system. No indication that either had any effect on the other. Now, thanks to this review, my plane not only sounds much better, it performs much better. The Common Sense 75 Opto ESC came with motor connectors already attached, but unfortunately they didn't quite match up with the connectors on the motor, so I got soldering practice.

I noticed no conflicts, problems or interference involving the ESC, the motor or the sound system.

Aerosound in Flight

Video Attempts 1 and 2

The first two attempts to shoot video and record sound in flight were less than successful because of high wind. On both occasions it was calm at my home when I left for the flying field, but during the hour long drive conditions changed. First the wind blew the sound away when the plane was downwind. The noise flying upwind was even worse. My new video camera's microphone was picking up a lot of wind noise, especially when facing into the wind, and that drowned out the sound from the plane on the recording. Although the sound had been very nice in person it was almost all wind noise on my videotape. Nothing to do but wait for a better day with less wind to fly.

Video Attempts 3 and 4

Deter, the mechanic who lives within me was distracted when connecting the four Lipoly packs to make a 5s2p arrangement to power my Dr-1. With his mind elsewhere, Deter created a short in the system. In two seconds he ended the flying session and destroyed two of the four battery packs. The plane got some burn marks, but there was no fire, just the end of session 3. Fortunately, a dry run was captured on video to give some idea of the sound.

Downloads

With my friend, Jeff Hunter, at the controls for an early morning flight, session 4 was attempted. The battery pack didn't supply enough juice and the planes bottom wing suffered some damage. A video that gives a taste of the sound is posted below.

Downloads

Visit Aerosound RC’s website where you will find several demo videos and demos for a variety of the motor sounds that they sell. The video clips really give you an idea of what adding sound can do for an electric powered plane.

Is this for beginners?

The installation could be done by a beginner, but I would recommend it be saved for a later plane. The fewer distractions the better for a new pilot. No sense putting this sound unit in a plane that is likely to undergo some rough landings. This unit is really geared more for the intermediate and expert pilots and the type and sizes of planes that they fly.

Conclusion

I was very impressed with how much more real my triplane seemed with the addition of the sound. It had a real WOW factor at the field. The motor start up and the machine guns opening up on the first low fly by grabbed every one's attention. The sound unit adds such a positive experience of realism it made me feel more professional with my plane. The sound unit has held up without any trouble in initial flights, but I know I will be adding a cooling heat sink to the amplifier and would recommend that one be bought with the initial unit, especially for those of us with very warm summer weather. I will also be buying a 4s1p small LiPo to power the sound system in the future. My amplifier is designed to work best with a 4s and I only had a 3s on hand. As Tim Allen wanted "More Power" on Tool Time; I now want more sound!

The system works great, and it really is very easy to connect and set-up now that I know what to do. Up until this review I was successful in fighting my urge to get a large World War II fighter with working retracts and a remote small bomb drop but I am afraid that sound killed my ability to resist because for an aviation buff they are as tempting as the mythical Greek Sirens who lured sailors onto the rocks with their sweet music. Too late, I already hear that Merlin motor sound in my head. I know there will have to be a Merlin engine sound in my future as I have already ordered the BH Spitfire from Hobby People. But that is another review for another day. In what plane would you like to have sound?

Pluses:

Electronics are easy to install

No indication of any electronic interference

A number of different motor sounds are available

The sound is really high quality and realistic

Bringing in another sense greatly adds to the sense of a plane's realism

Minuses

This quality sound doesn't come cheap (but it is good!)

Instructions could be more detailed for Dummies like me

My thanks to Jeff Hunter for flying my Dr-1 and to Aerosound RC for promptly responding to my e-mail.

The sound is impressive but the price is also. In the model railroad arena there are many sound units with even more effects that sell for much less but this is a good start. Granted the amplifier is a big part of the cost and nothing of that power is needed in the model rr application.

The big turn off for me is the sound card is not polyphonic or at least doesn't seem to be. When the machine guns are fired the motor sound is cut off - that's too bad as it takes away a lot of the effect.

Just my two cents - this is a good beginning and if popular I'm sure we will see more systems offered at better prices.

Hi Jim:
The machine guns do cut out the motor sound. It is a slight drawback. The motor sound is most impressive when the motor starts up and when you taxi back in and shut down. If you use the machine guns in shorts bursts most people at the field didn't even catch the motor cut-off when the machine guns opened up.
I start working on my motor mount/sound box for my BH Spitfire this weekend. I am delaying the review of the Spitfire slightly as it will not fly before it has sound installed and possibly the bomb drop working as well.
As I said in the review the sound doesn't come cheap but it is very good.
Mike

This is a very cool item...
but I don't think using plummers flux (acid) is a good idea. Use a 1/16 dia. 63/37 flux core solder made for electronic soldering and the wires will never turn green and fall apart.

Images

I am ALWAYS keen on new and cool stuff, and I jumped into this review with great anticipation?

This review is large, and has many links, but cannot find one video of a plane doing a fly by? Am I missing it (I viewed all videos twice) ???

How much do these two 4" speaker weigh - Alot? That is a pretty important question, but either the weight is hidden, or I'm just stupid and can find it any where in the review.

"Deter, the mechanic who lives within me was distracted when connecting the four Lipoly packs to make a 5s2p arrangement to power my Dr-1. With his mind elsewhere, Deter created a short in the system".

You're kidding right? What kind of connectors are your guys using on your batteries that you can actually create a short just by hooking them up for flight? (I have pre-made some "series" connectors and pre-made some "parallel" conectors. I use them all the time in the field. I don't see how you could short out your packs)?

So now it is your LAST session of the review, and the plane won't fly because the batteries were neglected to be charged ??? Really? That 1 foot flight was it? The whole in flight demo that I was looking for? (I'll take two - lol)

How are we supposed to judge anything good from that review?

Unless I missed the flying videos, and the important info (like how much the sound system weighs), I'd have to say YUK !!!

I was pretty excited when I saw all the "available sounds", but after reading the review, it does not seem really ready to be sold to the general public yet.

(I was hoping to see fly bys with all the sounds demoed, and you managed zero examples)?

The whole thing looked like it was a giant pain in the tail, weighed a ton, and didn't work worth dung unless you were standing there right next to it. (why did you guy's not post the first video)?

I am very interested in having a quiet electric .60 size Mustang come roaring by the flight line with a cool sound system like you guys describe. Let me know when the bugs are worked out, and your batteries are charged. Actually, after reading that review ..... I would never purchase a product like this without actually seeing it in person.

Funny thing is, I haven't even looked at the price yet. Don't care.

Sorry to be so negative, but that was the worst written review I have ever read on this site. Actually, it is the ONLY bad review I have read on this site, they are always good, (and sometimes a little biased ).
Jim

Each 4 inch speaker was 6.6 ounces.
The connectors used on the battery packs were Sermos connectors.
I had a perfect record until that day. I hope your record remains intact.
I directed you to their website and encouraged you to view their videos to make up for my short comings. Listen to the P-47 video for a very nice fly By.
The batteries were fully charged for the final flight but 4s didn't supply enough power compared to the 5s used previously.
As for weight I will be reworking to get the speaker up to the front and remove lead shown in the pictures used to balance the plane. It will take me time to save up the money for new 5s2p packs as December is a very expensive month in my family's fiscal calender. New batteries are by necessity a low priority for me. Mike

You know Mike ..... I apologize for being so harsh. I wasn't trying to be so negative, but as I wrote my reply, I just started to reflect back on the whole review, and spoke how I felt.

I am a webmaster, and can surely appreciate the enormous amount of time you put into that review. There was no lack of effort on your part, it was just a bad situation for you.

Can you imagine a lessor man, (without your know-how, contacts and help), trying to install that system on one of there prize Warbirds? What a total nightmare (you would have one pissed off customer for sure).

This product is a wonderful idea, but is clearly still in it's "developemental" stage, (not tweeked by a long shot ). In this particular situation, you weren't the "reviewer", but rather part of the "experimental team".

I hope I didn't offend you, because I sure do respect your effort and your willingness to help others. Thanks for your time Mike!

Well I honestly remain impressed with this product. I hope in the future it will be able to play multiple sounds simultaneously but I wasn't that concerned about that fact. I am going forward with a large Spitfire that will have the lovely Merlin sound in it. I honestly wouldn't have gone for the large Spitfire if I wasn't impressed with this sound system. It was the deal maker as discussed in my review. I am tempted to get the larger amplifier but I want to try a 4-cell Lipoly first and see what sound that power generates. I will be building a sound box/motor mount from the start for the Spitfire. I will be posting a review about the plane and all of its features when it is finished and flying. I have purchased the nine servos needed as well as a nine channel receiver and will have the basic plane finished except for motor and sound in another two weeks. If I had the proper tools my motor mount would be finished by then as well. As it is I will be going to a friends house to cut the parts for the motor mount and sound box sometime thereafter. Michael Heer